mm/memory-failure: simplify put_ref_page()

Patch series "Some cleanups for memory-failure", v3.

This series contains a few cleanup patches to avoid exporting unused
function, add helper macro, fix some obsolete comments and so on.  More
details can be found in the respective changelogs.  


This patch (of 13):

Remove unneeded page != NULL check.  pfn_to_page() won't return NULL.  No
functional change intended.

Link: https://lkml.kernel.org/r/20240612071835.157004-1-linmiaohe@huawei.com
Link: https://lkml.kernel.org/r/20240612071835.157004-2-linmiaohe@huawei.comSigned-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: kernel test robot <lkp@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/memory-failure.c

@@ -2120,14 +2120,10 @@ static inline unsigned long folio_free_raw_hwp(struct folio *folio, bool flag)
 /* Drop the extra refcount in case we come from madvise() */
 static void put_ref_page(unsigned long pfn, int flags)
 {
-	struct page *page;
-
 	if (!(flags & MF_COUNT_INCREASED))
 		return;
 
-	page = pfn_to_page(pfn);
-	if (page)
-		put_page(page);
+	put_page(pfn_to_page(pfn));
 }
 
 static int memory_failure_dev_pagemap(unsigned long pfn, int flags,